An attorney on special counsel Robert Mueller’s team was a writer for HuffPost, The Daily Caller News Foundation has found.

Aaron Zelinsky, a self-described Democrat, wrote nearly 50 articles as a contributor for the liberal news outlet from 2009 to 2014.

“I’m a Democrat,” he wrote in November 2012.

A review of his articles shows that he supported President Barack Obama’s efforts to close Guantanamo Bay, opposed President George W. Bush’s policy on torture, wrote in defense of gun control and argued for government-imposed limits on how much corporate executives can earn.

“Now is the time to begin enacting a progressive political agenda through the ballot box,” he wrote in a 2009 article on gay marriage.

Zelinsky, 34, has been writing political commentary since at least his undergraduate years at Yale University. As a member of the university debate team, he took a special interest in writing about presidential debates.

Zelinsky expressed support for Democratic candidate John Kerry before a 2004 general election debate. “From one Yale debater to another: Good luck, senator. I’m rooting for you,” he wrote in The Hartford Courant.

And he had encouraging words for Obama, wishing him good luck before a 2012 debate against Republican challenger Mitt Romney. “Stay relaxed up there,” Zelinsky wrote in a column. “You did the debate thing in 2008; it’s a piece of cake. No sweat.”

The Mueller investigation faced accusations of political bias after it was revealed that an FBI lawyer on the team had sent a colleague dozens of anti-Trump text messages.

In addition, Federal Elections Commission records, which only list contributions made at the federal level, show that nine of the 16 publicly-disclosed lawyers on the Mueller team have donated to Democratic candidates.

President Donald Trump has called the Russia investigation a political “witch hunt.”

Zelinsky, who joined the Russia probe in June 2017, is not among the nine attorneys to have made federal donations. But state records reveal a $100 donation he made to a Democratic committee in his home state of Connecticut in 2014, a couple months before he joined the Justice Department as a prosecutor.

He made another donation in 2016 – $100 to a local Democratic lawmaker.

Harold Koh, who worked for former Secretary of State Hillary Clinton as a senior legal adviser, has called Zelinsky a “fair-minded young prosecutor.”

“He is a professional, non-partisan straight shooter, who worked for Democrats at the State Department,” Koh told The New Haven Independent in June, “but has probably spent more years working for Republicans” like Supreme Court Justice Anthony Kennedy and Circuit Court Judge Thomas Griffith.

When Zelinsky started a blog on presidential debates in 2008, he told Yale News that he aspired for it to be non-partisan. “That is the most important feature of the blog,” he said. “Unlike a lot of television programs where we see talking heads plugging the candidates of the party with which they are affiliated, we work really hard to maintain objectivity.”

The blog is no longer available online, but his articles on HuffPost are overtly partisan and offer advice almost exclusively to Democrats.

After Democrats lost a special election in 2010, Zelinsky advised the party to keep calm and run strong candidates. “In November, every Democratic candidate must campaign hard,” he wrote. “The Democrats need candidates who want to run, not just those who want to win.”

And a common theme is his insistence that Democrats be more aggressive. “The Democrats are like the car-enthusiast who spends all of his time working on his sports coup without ever taking it for a spin,” Zelinsky wrote. “No one cares how fast you can go from zero to sixty if you never leave the driveway.”

He advised Senate Majority Leader Harry Reid in 2010 to play “hardball” with Republicans and use the threat of taking away the filibuster, known as the “nuclear option,” as a bargaining chip.

And he encouraged Obama to emulate the strong-arm tactics of former President Lyndon Johnson. “He wasn’t afraid to get down and dirty with the legislative branch, arm twisting, cajoling, and sometimes bullying senators to vote his way,” Zelinsky said of Johnson.

His articles also convey a certain pragmatism about politics, encouraging Democrats to reach across the aisle to find Republicans who could help advance a Democratic agenda. “There are Republicans the Democrats can, and should, work with,” Zelinsky wrote.

He only wrote one article on HuffPost giving advice to Republicans: stop “trying to deprive people of their basic human rights.”

“If you want to stay relevant, at least stop obsessively fighting marriage equality,” he wrote about gay marriage in 2012. “I’m not asking you to start supporting this basic human right, but maybe at least stop actively opposing it.”

The special counsel’s office declined to comment for this article beyond emphasizing that DOJ guidelines prohibit the use of political affiliation or ideology in making hiring decisions.